상향류 방식의 생물막 여과법(BAF)을 제지페수 처리에 응용하기 위해 하루 처리용량 100톤 규모의 파일롯플랜트를 설계/제작/운전하였다. 발포폴리프로필렌 담체를 미생물 고정 및 여과를 위한 여재로 도입하여 BAE에 충진하였는데, 제작된 BAE 반응기는 각각의 단면적이 1.5㎠인 두 개의 독립적인 폭기 필터로 구성되었으며 총 시스템의 높이는 6m였다. 본 연구의 목적은 BAF의 제지폐수 처리효율과 아울러 시스템 설계에 필요한 최적의 역세척 조건을 찾는 것이어서, 측정지표로 유입폐수/처리수의 COD, SS 농도 및 BAF 필터의 수두손실을 측정하였다. 연속 운전기간동안, 76-80%의 COD 제거효율 및 90-92%의 SS 제거효율이 안정적으로 유지되었으며 empty bed contact time 기준으로 약 0.85 시간까지 유기물 부하를 증가시켰을 때도 처리효율의 감소를 발견할 수 없었다. 역세척 후의 처리수의 soluble COD, SS농도를 측정했을 때, COD농도변화는 크지 않은데 비해 SS농도는 처리직후 급격히 상승하여 처리수질이 악화되었다가 점차 정상상태로 회복되는 경향을 보여주었다. 이와 같이 SS 농도가 변화하는 정도는 역세척수의 선속도에 의존하였는데 빠른 선속도로 역세척하였을 때 SS 농도의 변화율이 증가하였다.

Pilot plant experiments were carried out to study the steady and unsteady state behaviors of the upflow biological aerated filter(BAF) to remove organics and suspended solids from paper industry wastewater. Expanded polypropylene beads were used as the floating media for biomass attachment and filtration. The BAF pilot plant with a treatment capacity of 100 ton/day comprised two aerated filters which have cross sectional area of 1.5 ㎠ each and total height of 6 m. The COD and SS concentrations of the effluent and the head loss buildup of aerated filters were monitored to evaluate the treatment efficiency and to optimize backwash condition of the BAF system. The removal efficiencies of 76-80% for COD and 90-92% for SS were kept stable throughout the experiment. There was no significant difference in treatment efficiencies when the organic load increased up to 0.85 hour of empty bed contact time. The analysis of 55 concentration of the effluent after periodical backwash showed sharp increase right after backwash and gradual decrease to steady state while soluble COD was maintained nearly constant. The effluent concentrations and the required time intervals to reach steady state after backwashes were dependent on backwash conditions, like superficial linear velocities of backwash water. The higher the linear velocity of backwash water, the larger the deviation of SS concentration from steady state was obtained.

Backwash Biological Aerated Filter(BAF) Head Loss Upflow Paper Industry Wastewater

Adachi S, Fuchu Y, Water Sci. Technol., 24, 195 (1991)
Canler J, Perret J, Water Sci. Technol., 29, 13 (1994)
Pujol R, Hamon M, Kandel X, Lemmel H, Water Sci. Technol., 29, 33 (1994)
Rogalla F, Bourbigot MM, Water Sci. Technol., 22, 273 (1990)
Rovel J, Trudel J, Lavallee P, Schroeter I, Water Sci. Technol., 29, 217 (1994)
Stensel HD, Brenner R, Lee K, Melcer H, Rakness K, ASCE J. Env. Eng., 114, 655 (1988)
Yamayuki M, J. Water Waste, 34, 926 (1992)
Kim DJ, Kim GH, Cha GC, Lee KH, Lee YT, Lee TJ, Chem. Ind. Technol., 14(1), 40 (1996)
Kim DJ, Kim KH, Yoo IK, Lee KH, Lee TJ, Lee YT, Cha KC, J. Korea Soc. Water Quality, 13(2), 177 (1997)
Kang YT, Hyun KS, J. Korean Soc. Civil. Eng., 12(2), 285 (1992)
Lee KH, Chung EJ, Park TJ, J. Korea Soc. Water Quality, 12(4), 359 (1996)
"Advanced Treatment and Recycle System Development of Paper Industry Wastewater with BAF/Membrane System," SKEC Research Report (1998)
EPA, "Technology Assessment of the Biological Aerated Filter," EPA/600/2-90/015 (1990)